Device adapted to be secured to sewing machines for the production of zigzag seams



Sept. 15, 1953 G. UTZ DEVICE ADAPTED TO BE SECURED TO SEWING MACHINES FOR THE PRODUCTION OF ZIGZAG SEAMS FilecL Oct. 19, 1950 nil 2 Sheets-Sheet l Sept. 15, 1953 UTZ 2,652,015

DEVICE ADAPTED TO BE SECURED TO SEWING MACHINES FOR THE PRODUCTION OF ZIGZA'G SEAMs Filed Oct. 19, 1950 2 Sheets-Sheet 2 I 18 "I 23 1 -----I" I 17 2% r-kbf 1: 6 m 24: 44 17 I l I; 14 22 21 1s 49 w m 50 Patented Sept. 15, 1953 DEVICE ADAPTED TO BE SECURED TO SEW- ING MACHINES FOR THE PRODUCTION OF ZIGZAG SEAMS Georg Utz, Zurich, Switzerland Application October 19, 1950, Serial No. 190,962

The present invention relates to a device, capable of attachment to any sewing machine, for the production of zigzag seams, such device being secured in a readily detachable manner by means of a clamp screw to the presser bar provided on every sewing machine.

One object of the invention is to provide a device of compact design taking up little space and capable of being economically manufactured.

A further object is to provide the possibility of setting both the cloth feed and the width of the zigzag seam at will, within certain limits, whilst sewing.

Still a further object is to provide the possibility of sewing straight seams with the same device without removing the latter from the sewing machine.

These and other objects of the new device will be more readily apparent from the following specification in reference to the annexed drawing, in which a preferred embodiment of the invention is illustrated. In the drawing:

Fig. l is a lateral elevation from one side,

Fig. 2 is a lateral elevation from th side opposite to that of Fig. 1,

Fig. 3 is a section along the line 3-3 in Fig. 2,

Figs. 4 and 5 are sections along the lines 4-4 and 5-5 in Fig. 1.

Fig. 6 is a view of the device from below,

Fig. '7 is a view from the back side and,

Fig. 8 shows a diagrammatic view of the cloth feed bar.

Detachably secured to the pressure bar 2 of the sewing machine I is the clamping member 3, a screw 5 passin through the slot 4 in the clamping member 3 firmly holding the two m mbers together. The clamping member 3 is welded to the essentially U-shaped frame 6. This arrangement enables the zigzag attachment to be detachably fitted to the sewing machine. Arranged to rotate freely in the frame 6 is the main spindle 'l. Disposed between the cheeks B, 9 of the frame 6 is a control drum having a cylindrical mid-portion H and discs [2 and I3 arranged one on each side thereof. That portion of said discs which lies to the exterior of said mid-portion H is corrugated, and the discs are so arranged that a trough of the corrugation on the one disc faces a peak of the corrugation on the other disc. cam-race or control groove load which co-opcrates with a follower-roller l4. Said roller is rotatably mounted on an axle pin I which is in turn firmly attached to the rear end of a swivelling lever 16. The latter carries at its fore end This arrangement provides a 4 Claims. (Cl. 112160) the presser foot 11, which is provided with four longitudinal slots l8, one transverse slot 19, and a recess 20. Of the slots [8, the two outermost are visible in Fig. 3, whilst the two longitudinal slots located therebetween and behind the transverse slot IE] are concealed from view. The swivelling lever l6 swivels on a pivot pin 2! secured to a slide bar 22. The latter carries at its rear end a bolt 23 guided in a slot 24 in the frame E. The lengthwise movement of the slide bar 22 is produced by an arm 25 swivelling on the pin 25 in the frame 6 and embracing the bolt 23 by a small slot not shown in the drawing. Thus, swivelling of the arm on the pivot 26 causes displacement of the slide bar 22 and with it of th pivot pin 2| firmly attached thereto, in the lengthwise direction. This movement of the arm 25 and consequently of the slide bar 22 accordingly shifts the pivotal point of the lever I6. As the rear end of said lever is guided with the roller M in the cam-race of the control drum H), displacement of the pivotal point 2| results in the stop of the presser foot I! being displaced in the transverse direction on rotation of the control drum. Upturned lugs 21 of the slide bar 22, which in one of their end positions encounter the rear end 28' of the swivelling lever I6, limit the travel of said slide bar 22, whilst the other end position is determined by the rear end of the slot 24.

Rotatably mounted on the spindle l exteriorly to the discs 12 and I3, are lugs 28, 29 of a hood 36. The latter is rigidly connected to the fork lever 3 I, which consequently pivots freely on the spindle l. The slot 32 embraces a bolt 33 in the needle bar 34, with the result that as the needle bar 34 performs its vertical reciprocatory motion, the fork lever 3| swivels on the spindle l. The fork lever 3| carries a pawl 35 swivelling on the pivot 36 and acted upon by a torsion spring 3? which tends to twist it in the clockwise direction. The free end of the pawl 35 is forked, having a longer extension 38 and a shorter nose or stub 39. The latter co-operates with the ratchet wheel 4i! which is rigidly mounted on the spindle i. If the fork lever 3| is swivelled in the counterclockwise direction, the stub 39 slides over the teeth of the ratchet wheel 40. If, on the other hand, on an upward movement of the needle bar 34, the fork lever is swivelled in a contrary direction, the stub 39 is forced by the torsion spring 3? into a gap between teeth of the ratchet wheel 40 and rotates the latter, and with it the spindle l and the control drum [0 mounted thereupon, in the clockwise direction. The longer extension 38 embraces a lateral projection 4| of a slide bar 42 guided by a slot 43 on two screws 44 in such a way as to be vertically slidable. Said screws 44 are screwed into the cheek 8 of the frame 6. At the upper end of the slid bar 42 is a lug 45 parallel to the projection 4| and bent over, its purpose being to serve as a grip for adjustment of the slide bar 42. As will readily be seen, when the slide bar 42 is in its lifted position the pawl 35 is likewise lifted and thus out of engagement with the ratchet wheel 40.

The forked lever 3: further exhibits a lug 46' which co-operates with a roller 4? on an anglelever 48. Said lever 48 swivels on the pin 49 and is provided at its fore end with a presser foot 50 which co-operates with the cloth feedbar still to be described.

The lug 28 of the hood 30 exhibits two stops El, 52 produced by bending over the material. These stops co-operate with bent-over lugs 53, 54 of a two-armed lever 55. The latter embraces by a slot 56 the bolt 5'! of the screw 58. Said screw bolt 5'! is guided by a square portion in a slot 60 of the pusher bar 65, which is guided by means of the slots 62 in such a way as to be slidable on the screw bolts of the screws The: screws are screwed into the cheek 9 of the frame 6. By turning the screw 58, the screw bolt 57 can be fixed in various positions in the slot 56 of the two-armed lever 55 and in the slot of the pusher bar El. The cloth feed bar 54 is rigidly connected to the pusher bar 6! by means of the screw 55. The pusher bar 6! is provided for this purpose with a bent-over lug 65. The magnitude of the feed provided by the cloth feed bar 54 can be adjusted by slackening, adjusting and retightening the screw 58, for, according to the position of the square member 59 constituting a slide block, the displacement of the pusher bar 65, and therefore of the cloth feedbar 64, caused by the stops 5!, 52 encountering the stops 53, 54, varies.

The cloth feed bar comprises at its fore end a transverse member from which toothed members 55 project downwards through the lengthwise slots in the presser foot l? and beyond the latter and in their reciprocatory motion, take with them the piece of cloth to be sewn.

The device described functions as follows:

The piece of cloth, not shown in the drawing, which is placed on the throat plate 6'! and is to e provided with a zigzag seam, is forced firmly against said throat plate 6? by the presser foot If during the downward movement of the presser bar 2. At the same time the needle 63 is lowered and, at the end of its motion, enters the transverse slot 19. During this downward motion of the needle bar 34, the bolt 33 swivels the forked lever 31 on the spindle T, the pawl 35 thereupon snapping by its stub 39 into the gap behind the nearest tooth of the ratchet wheel At the same time the nose 46 moves from the position shown in Fig. 1 into a position in which it no longer bears against the roller 4?. The latter, and with it the angle lever 48, is therefore enabled to swivel in the clockwise direction, with the result that the presser foot 59 can lift from the cloth feed bar 64 on whose cross member 65 it is bearing. During the same downward motion of the forked lever 3|, the stop 52 presses against the stop 54, causing the two-armed lever 55 to be swivelled more or less in the clockwise direction, and the pusher bar 8! displaced to the right, according to the position of the screw bolt 51.

When the needle bar 34 moves upwards, the stub 39 of the pawl 35 turns the ratchet wheel 40, and with it the control drum to, forwards in the clockwise direction. Through this the roller [4 is displaced laterally by the camrace of the control drum I0, this resulting in a swivelling motion of the swivelling lever 16 about its pivotal point 2|. The presser foot 2'! participating in this motion shifts to one side the cloth lying on the throat plate 611', since the needle 68 has been withdrawn from the cloth in the course of the upward motion of the needle bar 34. During this upward motion of the needle bar 34 and accordingly of the end engaging therewith of the forked lever 3|, the nose 46 again engages behind the roller 41. The angle lever 48 is thereby swivelled in the counterclockwise direction and the presser foot 50 forced against the cloth feed bar 64 and the latter against the cloth. The swivelling of the forked lever 3! caused by the upward motion of the needle bar has the further consequence that the stop 5! presses against the stop 53 and swivels the two-armed lever 55 in the counterclockwise direction. This results in a rearward movement of the pusher bar 5|, which moves, in Fig. 2, from right to left together with the cloth feed bar 64. The cloth is in this process, simultaneously with the lateral displacement, fed forward by the cloth feed bar 54, which is provided with teeth on its lower side, by an amount which can within certain limits be set by means of the screw 53, since in the meantime the presser bar 2 with the presser foot 5? has been lifted.

As has already been mentioned, the pivotal plant of the lever 16 can be displaced by swivelling the arm 25. The result of such displacement is that the swivelling motion of the presser foot 5! which shifts the cloth to the side, and accordingly the width of the zigzag seam, can be set as desired within certain limits. As a result of the arrangement of the arm 25, this adjustment can be effected during sewing without interrupting the work, which on. the one hand affords a saving of time and on the other enables very special effects to be achieved.

In addition to the width of the Zigzag seam,

- the amount of feed of the cloth can also be set,

namely by the adjustment already described of the screw 58. When the screw bolt 5'. is at its lowermost position in the slot 55, the feed is at its minimum, whilst if said bolt 57 is at the top of said slot 56, the maximum feed is provided.

By raising the slide bar 42 the pawl is shifted in the counterclockwise direction against the action of the spring 31, and the stub 39 comes out of engagement with the ratchet wheel 48. The latter, and with it the control drum i0, is therefore not rotated, and the swivelling lever l6 and the presser foot I! accordingly not displaced. It is therefore possible to sew straight seams without having first to remove the device from the machine. To secure the slide bar 42 its raised position, the arm 25 is swivelled forwards, i. e. in the clockwise direction as seen in Fig. 3, with the result that its shoulder 79 comes into position below the lug or heel H of the slide bar 42, thus preventing the latter from dropping of its own accord.

The device described may be readily fitted to any sewing machine. The clamping member 3 is so designed as to suit all sewing machines. The feed dog provided on all sewing machines is not required whilst the device described is use, as the cloth is guided forwards and sideways by the presser foot H and the cloth feed bar 54. In sewing machines with lowerable fee-d dogs, the ordinary throat plate is usually replaced by another plate pierced only by the needle hole. This enables the cloth to slide sideways more efliciently. In the case of sewing machines in which the feed dog cannot be lowered, the latter is expediently covered by a cover plate. Through the incorporation of the cloth feed bar 64 in the presser foot ll, even stockinet material and very thin fabric can be provided with a zigzag seam.

What I claim is:

1. In a sewing machine attachment for the production of zig-zag seams, a frame means for securing said frame to the presser bar of said machine, a forked lever pivotally connected to said frame, means for rotating said lever in response to reciprocatory movement of the needle bar of said machine, a pawl journalled on said forked lever, a control drum pivotally mounted in said frame, a ratchet wheel secured to said control drum for cooperation with said pawl, a spring urging said pawl towards said ratchet wheel, a presser foot, means pivotally and slidably connecting said presser foot to said frame, means on said control drum for imparting a transverse swinging movement to said presser foot upon rotation of said control drum, a slide bar reciprocally mounted in said frame adjacent the pawl, and means on said slide bar mounted to engage said pawl to move it out of engagement with said ratchet wheel against the action of said spring.

2. An attachment as in claim 1, in which said pawl has two projections, one extending into the path of said ratchet wheel, and the other extending into the path of said pawl engaging means on the slide bar.

3. In an attachment as in claim 1, a second slide bar reciprocably mounted in said frame, means for adjusting said slide bar longitudinally of said frame, and a pin on said slide bar forming said pivotal connection between said presser foot and said frame.

4. In an attachment as in claim 1, a second slide bar, an arm pivotally connected to said second slide car, means pivotally and slidably connecting said arm to said frame, guide means in said frame for said second slide bar, and means on said first slide bar for engaging and locking said arm, so as to prevent movement of said arm and said second slide bar.

GEORG U'IZ.

References Cited in the file of this patent FOREIGN PATENTS Number Country Date 489,405 Germany Jan. 16, 1930 260,831 Switzerland Apr. 15, 1949 

